Long time in awful dry season: important to plant in it (7,5)
I believe the answer is:
donkeys years
'long time' is the definition.
(I've seen this before)
'awful dry season important to plant in it' is the wordplay.
I cannot really see how this works, but
'important' could be 'key' (similar in meaning) and 'key' is found in the answer.
'it' could be 'e' ('e' can mean 'electronic' which is similar to 'IT') and 'e' is found in the answer.
This may be the basis of the clue (or it may be nonsense).
'in' is the link.
Can you help me to learn more?
(Other definitions for donkeys years that I've seen before include "A beastly long time" , "What's evident in old ass" , "An age" , "Yonks" , "forever" .)